Portable sink



FIG. 1 is a perspective view of a portable sink showing my new design with the cover open and broken away for convenience of illustration;

FIG. 2 is a top plan view thereof with the cover closed;

FIG. 3 is a front elevational view of FIG. 2;

FIG. 4 is a top plan view thereof with the cover removed;

FIG. 5 is a left side elevational view of FIG. 4;

FIG. 6 is a right side elevational view of FIG. 4; and

FIG. 7 is a front elevational view of FIG. 4. 

The ornamental design for a portable sink, as shown and described. 